1. Field of the Invention
Expanded graphite material.
2. Art Background
In the prior art, various forms of graphite material have been used to give charge carrying or dissipating capacity to polymers. Graphite material has been used to enable polymer material to conduct or dissipate electrostatic charge and the like.
One of the first such graphite insulating materials was powdered carbon black which had an appropriate amount of electrical conducting capacity, but was very difficult to handle, relatively heavy, and extremely time consuming to replace. As a result of the advent of polymer chemistry, a number of newer materials were developed which are lighter and easier to handle, but which have the requisite electrical current carrying capacity. One such material is a carbon fiber insulating material made of a carbon fiber held in a matrix by a polymer material, and formed into a board, block or other object.
U.S. Pat. No. 5,582,781 discloses, inter alia, a method of making graphite foam material. Expanded graphite is made from flexible graphite foil. The expanded graphite is then compounded into sheets to make a thermally insulative material.
U.S. Pat. No. 5,882,570 discloses, inter alia, a method of injection molding graphite and a thermoplastic material. This method also uses 45 to 60 percent by weight expanded graphite. The compound of thermoplastic material and re-expanded graphite is fed into a molding system (e.g. an injection molding system) at relatively high temperature and injected into a mold where a plastic material is formed. The material is valuable for its heat insulative capacity for use in for example, furnaces and other apparatus.
As the above paragraphs indicate, there is a market for commercialization of graphite-based articles. Thus, improved techniques of forming graphite materials, particularly expanded graphite materials, are desired.